You give it the short_citation_author and short_citation_year and it will return all the short_citation_tiebreakers found in use for that combination. If null is used, it will show 'null'. If the same tiebreaker is used multiple times, it will show multiple times, even if it's 'null'. Here's an example:

Select inuse_tb('Smith', 1990) from dual;

In Central Biotics database, you'll get this back:
null, 01, 01, 01, null, null, null, null, null, null, null, null, null, 02, 01, null

Another example:
select REFERENCE_CODE, INUSE_TB(short_citation_author,
short_citation_year)
from reference
where REFERENCE_CODE LIKE 'N91FW%';

NOTE:The input author name IS case sensitive. And the function will only return about 4000 characters, which should be sufficient for most uses.

To add this to your database, logon to SQL+ as the biotics_user. Copy and paste the code in the attachment into the window and hit enter. You should get 'Function created'. Then you should grant permissions to all your users with this entry:
GRANT EXECUTE ON INUSE_TB TO PUBLIC;